Unbreakable Vow

[exodusts]

No: HPFGUIDX 147996

> David:
> Hi all,
> I have a few quesitons about Unbreakable Vows:
> 1. Can a person make more then one Unbreakable Vow?
> 2. If the answer to question 1 is yes, then can a person make an 
> Unbreakable Vow which conflicts with another?  For example, what if 
> Snape had made an Unbreakable Vow with Dumbledore not to harm 
Harry, 
> and then later made an Unbreakable Vow with someone else that he 
would 
> harm Harry.  What would happen?  Would the second vow just 
> not "take."  Would it still look like a vow was being made to an 
> observer?
> 

Exodusts:
Logically, the following MIGHT happen:
Snape takes 1st vow with X: "I will never kill Dumbledore".
Later, Snape takes 2nd vow with Y: "If necessary, I will carry out 
Draco's mission (to kill Dumbledore)".
Theoretically, Unbreakable Vows are unbreakable, without incurring 
the consequence. Therefore, at the moment it becomes apparent (to 
him / whatever power triggers / arbitrates UVs) that killing 
Dumbledore is unbreakably possible, for him (i.e. the moment he 
swears the 2nd vow), he has broken the 1st. He will immediately 
suffer the consequences of vow 1. If he survives, he will also be 
bound by vow 2.

A simpler magical rule might exist that a person can never be subject 
to more than one UV at any one time, meaning the 2nd spell would just 
fail, but I do not think there is anything in canon to categorically 
state that.

PS A more amusing question to ask is why, since we know from Viktor 
Krum (in GoF) that Imperiused-persons can themselves cast 
Unforgivable Curses, Voldemort doesn't just take over the world using 
an army of daisy-chained Imperius victims?